DESCRIPTION: (From Investigator's Abstract) The olfactory bulb is the first synaptic relay in the olfactory pathway, and its function is critical to the detection and discrimination of odors. Loss of normal olfactory function has been associated with nutritional deficits, among other health concerns. In addition, the olfactory bulb is a promising model for understanding sensory processing and perception by the brain. The proposed research will investigate the patterns of neural activity responsible for encoding odor information in the brain. The specific aims of this research are to understand the importance of coherent, odor-evoked oscillations of olfactory bulb activity in odor discrimination, the neural basis for these oscillations, and the relationship between odor-evoked oscillations and a separate, spatial code for representing odor information at the level of the olfactory bulb. The study will use optical imaging with activity-dependent dyes in order to characterize the temporal and spatial patterns of activity in the intact, in vivo olfactory bulb of the turtle. Experiments are proposed to address the temporal and spatial representation of odors by specific populations of olfactory bulb neurons and to test the role of oscillations in mediating odor discrimination at the behavioral level. This work will help elucidate how the olfactory bulb represents odor information and what parameters of olfactory bulb activity are important for discriminating odors.